This invention relates to a process and apparatus for separating heavy metals such as mercury, gold, platinum, lead, rhodium, osmium, palladium, silver, etc., in the free state from their associated ores. In some instances, the metal may be present in mine tailings which heretofore had little, if any, commercial value because of the large recovery costs, and hence were abandoned. In other instances, the metal may be present in a natural occurring ore body, but not of sufficient size to permit economic recovery by conventional processes.
Various types of apparatus have in the past been employed to recover precious metals such as gold from mine tailings raw ore, etc., using water washing techniques. One type of apparatus employed an inclined grooved wheel separator to which was fed a supply of ore that was then water washed. Gold particles sank to the bottom of the grooves, and when the wheel was rotated, the gold was moved upwardly along the grooves from the periphery of the wheel to a central orifice where it was recovered.
The basic problems when using a single wheel device or a plurality of such devices involved the necessity of feed augers for every wheel and the necessity for maintaining a uniform feed to each wheel. Also, once the beneficiated ore was removed from a wheel, it tended to dry out in a non uniform fashion; this made it difficult to feed it uniformly to a succeeding wheel even when employing a mechanical device such as an auger.
Furthermore, the use of a plurality of single separator wheel devices produced a spectrum of ore grades each of which had to be treated differently.
Consequently, the various prior art devices were limited in overall efficiency and many bodies of ore tailings still exist which contain gold and other precious metals but which heretofore could not be further economically refined with the available apparatus.
In Applicant's copending U.S. application Ser. No. 613,366, filed Sept. 15, 1975 now U.S. Pat. No. 4,008,152, there is disclosed a process and apparatus for separating heavy metals from ore employing at least three separator wheels driven from a common mounting.
However, when capital costs are included, the separator wheels are an expensive component of the apparatus.
It is therefore an object of this invention to employ fewer separator wheels and still retain the essential benefits of the invention disclosed in my copending application without undue detriment to process economics.
Another object is to provide wash water actuation which coincides with operation of the separator wheels.
Another object is to provide simultaneous alteration of the wheel inclination when in operation.
Another object is to augment the separating action by employing mercury as a phase separator.
Another object is to provide simultaneous operation of the wheels and wash water pumping and also to permit disengagement of the wheels from the drive shaft while still continuing to apply wash water to the separator wheels.
Another object is to provide a separator wheel with a unique groove design.
Other objects of this invention will become apparent from the description and drawings to follow.